Should You Be Adding Magnesium to Your Water?

An expert weighs in on the latest TikTok health claim.

April 19, 2023

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Photo by: SimpleImages/Getty Images

SimpleImages/Getty Images

Sleep is one of the stepping stones to a healthy lifestyle. If you’re having trouble sleeping, one of TikTok’s latest trends recommends drinking a glass of water with 400 milligrams of magnesium in order to improve sleep quality. Other touted benefits include waking up happier, reducing stress and reducing water retention. But is the latest trend worth trying, or simply skipping? Here’s an expert look.

What Is Magnesium?

Magnesium is a mineral that’s naturally present in many foods, added to foods, found as a dietary supplement, and even added to some medications, like antacids. It’s needed for many metabolic reactions, and is a helper in more than 300 enzyme systems in the body, including making protein, muscle and nerve function, blood sugar control and more. It also helps with the structure of bones and a normal heart rhythm.

How Much Magnesium Do You Need?

The recommended dietary allowance for magnesium varies by age and gender:

  • Men (19-30 years): 400 mg
  • Women (19-30 years): 310 mg
  • Men (31 years and older): 420 mg
  • Women (31 years and older): 320 mg

What Foods Have Magnesium?

Magnesium is found in plant and animal foods, and beverages. Green leafy vegetables (like spinach and kale), legumes, nuts, seeds and whole grains are all good sources. The rule of thumb is that foods that contain fiber also provide the mineral. Magnesium is also added to breakfast cereals and other fortified foods. Below are the amounts of magnesium you can find in a variety of foods:

  • 1 oz. pumpkin seeds = 156 mg (37% daily value)
  • 1 oz. chia seeds = 111 mg (26% daily value)
  • 1 oz. dry roasted almonds = 80 mg (19% daily value)
  • 1/2 cup boiled spinach = 78 mg (18% daily value)
  • 1 cup plain or vanilla soymilk = 61 mg (15% daily value)
  • 1/2 cup cooked shelled edamame = 50 mg (12% daily value)
  • 2 Tbsp smooth peanut butter = 49 mg (12% daily value)

Tap, mineral and bottled waters can also be sources of magnesium, but vary by source and brand. They usually range from 1 mg/L to over 120 mg/L, so be sure to check the nutrition facts label.

Are You Getting Enough Magnesium?

The 2013-2016 National Health and Nutrition Examination Survey (NHANES) found that 48 percent of Americans of all ages take in less magnesium from food and beverages than the estimated average intake (EAR is the average daily level of intake estimated to meet the requirements of 50 percent of healthy individuals and is used to assess nutrient intake of an individual). Adult men 71 years and older, and adolescent males and females are more likely to have lower intakes.

Since kidneys limit how much magnesium is let out of the body, magnesium deficiency caused by low diet intake is uncommon in healthy individuals.

However, there are certain health conditions that can lead to magnesium deficiency – including gastrointestinal (GI) disease, type 2 diabetes, alcohol dependence and aging. Crohn’s disease, celiac disease and other GI issues that involve chronic diarrhea and fat malabsorption can lead to magnesium deficiency over time. There tends to be an increase in magnesium lost in urine in people with insulin resistance and type 2 diabetes (especially when blood sugar isn’t controlled). Chronic alcoholism can lead to magnesium deficiency due to poor dietary intake and GI issues like vomiting, diarrhea and fatty stools. Older adults tend to have lower dietary intake of magnesium. This, compounded with health issues, chronic disease and medications, can lead to a deficiency.

Should You Take Magnesium Supplements?

You can find magnesium supplements in a variety of forms including magnesium oxide, citrate, chloride and glycinate. Absorption of magnesium varies between supplements. Forms that dissolve well in liquid are better absorbed by the gut, compared to less soluble forms. Magnesium in the forms of aspartate, citrate, lactate and chloride are absorbed better than magnesium oxide and sulfate. Zinc supplements can also interfere with magnesium absorption.

The tolerable upper level of magnesium for men and women is 350 milligrams per day. Taking more than that regularly can result in toxicity, which can lead to nausea, vomiting, facial flushing, urine retention, depression and lethargy. Extreme toxicity can then progress to muscle weakness, difficulty breathing, irregular heartbeat and even cardiac arrest.

Magnesium supplements can help with some health conditions. High blood pressure is a major risk factor for heart disease and stroke. Research has found that magnesium supplements can lower blood pressure, but only marginally. Research has also found that people with diets high in magnesium have a significantly lower risk of type 2 diabetes.

Research has also shown that magnesium deficiency may be a risk factor in osteoporosis (brittle bones). One study found a positive association between taking magnesium and bone mineral density in both genders, while another study found that women with osteoporosis have lower blood magnesium levels compared to women who do not have osteoporosis.

As magnesium and sleep have been getting a lot of attention, a 2023 systematic review study revealed that according to observational studies, there seems to be an association between how much magnesium you have and sleep quality with relation to falling asleep during the day, sleepiness, snoring and how long you sleep. However, clinical trials showed to have an uncertain association between magnesium supplementation and sleep disorders. Researchers suggested that more research is needed to determine whether taking magnesium supplements affects sleep patterns. A well-designed, randomized clinical trial with a larger sample size and longer follow up times (more than 12 weeks) is needed to help clarify whether a relationship exists.

In terms of anxiety, a 2020 published systematic review concluded that there is no significant association between blood magnesium levels and generalized anxiety disorder.

Should You Follow the Magnesium Water TikTok Trend?

One TikTok user said that after one day of taking magnesium, her anxiety went away. However, it takes weeks or even a few months’ worth of supplements for that to really work. In addition, the recommendation of taking 400 milligrams of magnesium per day with a glass of water can lead to several possible harmful effects. The upper limit per day of magnesium is 350 milligrams per day. And remember, magnesium is found in food and water, as well, so if you’re adding 400 milligrams of it to your water, you’re taking well over the daily recommended amount.

If you do this regularly, and maybe even take a fortified beverage or other supplements with magnesium, you may possibly experience toxic effects. In addition, magnesium can interact with numerous medications, including alendronate (or Fosamax), used to treat osteoporosis, as well as antibiotics, like demeclocycline, doxycycline, ciprofloxacin and levofloxacin. Some diuretics and proton pump inhibitor drugs like Nexium and Prevacid can lead to low blood magnesium if taken for a long period of time.

Bottom Line: Taking magnesium and water will not make you sleep better or help make you happier. You can get plenty of magnesium from water and a well-balanced diet of healthy foods. There is no need to take magnesium supplements. If you’re not sure, talk to a health professional or registered dietitian.

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